Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent upon growth which occurs when turgor pressure is above a threshold level. Since growth after planting is influenced by nursery cultural practices,...
In study 111, four Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stocktypes (1-0, 2-0 standard nursery run and low density bareroot seedlings, and 1 year old container stock) were outplanted in a randomized
incomplete block design to an old field in the Willamette Valley of Oregon in a factorial experiment t4 stocktypes...
One of the largest problems facing the forester in the Pacific Northwest today is the economical, rapid rehabilitation of cut-over lands. Many of these cut-over lands are planted to Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. Previously, both aerial and spot seeding techniques have been evaluated for their efficiency in Douglas-fir regeneration....
A quantitative and predictive measure of seedling vigor during the regeneration chain would be of utmost help for forest regeneration work. This was the impetus
to study the possibility of using abscisic acid (ABA) concentration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) needles as an indicative measure of seedling vigor prior...
The physiological and biochemical responses of Douglas-fir seeds to stratification, redrying, storage and subsequent germination were determined. Stratification increased seed vigor, embryo and gametophyte
phosphorylative efficiency and RNA synthetic ability. Redrying seems to increase the rate of enthryonic nucleic acid synthesis, speed of germination and seedling vigor. ATP, total adenosine...
A rapid and efficient procedure that required no partitioning was developed for the purification of abscisic acid (AbA) from the needles of Douglas-fir seedlings. Extracted needle pigments were removed by a
PVP column and the eluted AbA was concentrated on a DEAE column. The AbA was eluted from the DEAE...
Preliminary fertilization trials with western hemlock have yielded responses which vary significantly from stand to stand, especially in areas near the Pacific Coast. Growth responses have varied from positive to negative in an erratic manner. Previous data did not permit validation of such hypotheses as, "the application of fertilizer
to...
Chapter 1 Growth and Survival of Root-Wrenched Douglas-fir Seedlings Root wrenching of seedlings (severing the roots 15 cm below the soil surface) was investigated as a nursery practice to improve growth and survival of field-planted Douglas-fir from six local seed sources
in the Pacific Northwest. At lifting, shoots of wrenched...
The physiology of dormancy of western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings was examined. Many areas proved to exhibit similarities to those elucidated for Douglas-fir, although significant differences were also found and necessitate the use of caution in extrapolating data from one species to the other.. Dormancy of western hemlock...
Oscilloscope display of modification of a square wave signal passed through stem tissue was evaluated as a means of detecting depth of dormancy and survival potential of coniferous seedlings. Trace form did not change during release from deep dormancy in Douglas fir. This release was judged by observing speed of...
